termination of an open end employment contract
I have a job that I want to quit. I started working July 2012 and there was a time limited contract until June 2017 (so I have been working on a temporary contract for 4 years and 11months). Now I will sign a new an open-ended contract starting from July 2017. My salary is around 45K EUR. In the same time, I have received a new offer to change the company starting from Dec 2017. I would like to resign the new open-end contract which starts in July 2017. What would be the notice period for which I will need to inform the employer before I quite?
During this time the notice period was agreed to be 1 week from both sides. Now I am trying to use this clause and resign, but my employer is stating that the new law that entered in force 1.1.2014 actually requires 9 weeks of notice from my part (6 weeks for seniority and 3 weeks for overlap period). Is this true? I need to get rid of this job quickly or I'll loose the job offer I got (from another country). Is this new law applicable even if I have not signed a new contract?